I used preupgrade to go from F10 to F11 on my Macbook pro (intel). Everything seemed to work, but after the final restart the "windows" icon wasn't visible in bootcamp. Booting the live cd and running gptsync on /dev/sda fixed it.
preupgrade doesn't touch the partition table, and it specifically directs anaconda *not* to reinstall the bootloader, by using 'bootloader --upgrade --location=none'. Is anaconda supposed to run gptsync? Maybe telling it not to install the bootloader causes it to forget to run gptsync?
*** This bug has been marked as a duplicate of bug 503149 ***